Quicktime Xvid Support
April 9, 2007
Apple Quicktime now officially supports the xVid video format. The Xvid component for QuickTime allows users to play & encode Xvids in QuickTime Player. Xvid is a video codec library following the MPEG-4 standard.
Xvid can be considered as a ZIP for video. But unlike ZIP, Xvid is not lossless. That means that a video after compression and decompression with Xvid won’t be identical to the original source. Typically however, a difference to the source is visually imperceptible.
So Xvid removes information that is not important for human perception, which is somewhat similar to MP3 for audio. This enables very high compression rates that allow to effectively work with digital video on home computers at all. To give an example: uncompressed digital video is huge and requires about 100 GB per hour at PAL resolution.
The same video would require just 500 MB per hour at very high quality when compressed with Xvid. That is a compression ratio of 200:1. It should be noted that support has only been added to Quicktime and iTunes and AppleTV are not yet supported. More here.
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